NASHUA — One person is dead after an explosion rattled a Carlisle Road neighborhood Wednesday afternoon, followed by a massive fire that destroyed a city residence.

Fire officials are not yet releasing the name of the individual found dead in the rubble of the house at 7 Carlisle Road. An autopsy will be conducted Friday morning, but in the meantime, fire officials say they are not providing the gender or age of the victim until family members can be notified.

."There was a gas pressure explosion, and the heat was very tremendous," said Max Schultz, assistant state fire marshal. "We don't know if it was intentional or accidental."

City firefighters were called to the two-story residence shortly after 2 p.m. for a reported explosion and fire. Schultz said he is unsure whether an initial search of the home took place when firefighters arrived..."From the extensive damage, I can tell there were a lot of flames," he explained.

The explosion blew off a side wall of the house, according to Schultz, who said a garage door also separated itself from the structure...Once crews were able to extinguish some of the blaze and firefighters were able to get inside the building. It was then the victim's body was discovered, said Schultz, who would not say where in the house the person was found...Two friends of the victim gathered at the fire scene Wednesday evening, but left before the body was removed. The state medical examiner was at the scene, along with state fire officials and a remaining crew of Nashua firefighters..."I don't know what else to say. I am heartbroken," said one of the victim's friends, who did not provide his name. "I don't want to say anymore than that."

The heat melted the siding of the house next door to the corner lot. However, on the other end of the home, flowers were still blooming on a vine that clung to a second-floor deck..."I heard the explosion, and I thought it was an accident or a car had hit a tree," said Helen "Mike" Knapp, who was sitting in the living room of the home directly across the street from the fire.

"I looked out and flames were coming out of everywhere, out of all the windows," she said. "The heat was so intense, I didn't go outside."..Officials from Liberty Utilities were on Carlisle Road working to shut off the gas line to the house. Maureen Kirk, a spokeswoman for the company, said service to other homes in the neighborhood would be not affected...khoughton@newstote.com